Operatives of the shadowy covert organization SIGMA Force, Dr. Lisa Cummings and Monk Kokkalis search for answers to the bizarre affliction aboard a cruise liner transformed into a makeshift hospital. But a sudden and savage attack by terrorist hijackers turns the mercy ship into a floating bio-weapons lab.

Time is an enemy as a worldwide pandemic grows rapidly out of control. As the seconds tick closer to doomsday, SIGMA's commander, Gray Pierce, must join forces with a beautiful assassin who tried to kill him--following the trail of the most fabled explorer in history into the terrifying heart of an astonishing mystery buried deep in antiquity and in humanity's genetic code.